diff --git a/sakura_core/doc/layout/CLayoutMgr.cpp b/sakura_core/doc/layout/CLayoutMgr.cpp
index fcbc59c600..dc09c52a1e 100644
--- a/sakura_core/doc/layout/CLayoutMgr.cpp
+++ b/sakura_core/doc/layout/CLayoutMgr.cpp
@@ -873,8 +873,6 @@ void CLayoutMgr::LogicToLayout(
 				else{
 					nCharKetas = GetLayoutXOfChar( pData, nDataLen, i );
 				}
-//				if( nCharKetas == 0 )				// 削除 サロゲートペア対策	2008/7/5 Uchi
-//					nCharKetas = CLayoutInt(1);
 
 				//レイアウト加算
 				nCaretPosX += nCharKetas;
@@ -1007,8 +1005,6 @@ checkloop:;
 		else{
 			nCharKetas = GetLayoutXOfChar( pData, nDataLen, i );
 		}
-//		if( nCharKetas == 0 )				// 削除 サロゲートペア対策	2008/7/5 Uchi
-//			nCharKetas = CLayoutInt(1);
 
 		//レイアウト加算
 		if( nX + nCharKetas > ptLayout.GetX2() && !bEOF ){
diff --git a/sakura_core/doc/layout/CLayoutMgr_DoLayout.cpp b/sakura_core/doc/layout/CLayoutMgr_DoLayout.cpp
index 2de5300a63..10973b8f5d 100644
--- a/sakura_core/doc/layout/CLayoutMgr_DoLayout.cpp
+++ b/sakura_core/doc/layout/CLayoutMgr_DoLayout.cpp
@@ -49,12 +49,12 @@ static bool _GetKeywordLength(
 	CLogicInt nWordLen = CLogicInt(0);
 	CLayoutInt nWordKetas = CLayoutInt(0);
 	while(nPos<cLineStr.GetLength() && IS_KEYWORD_CHAR(cLineStr.At(nPos))){
+		CLogicXInt nCharSize = CNativeW::GetSizeOfChar( cLineStr, nPos );
 		CLayoutInt k = cLayoutMgr.GetLayoutXOfChar(cLineStr, nPos);
-		if(0 == k)k = CLayoutInt(1);
 
-		nWordLen+=1;
+		nWordLen += nCharSize;
 		nWordKetas+=k;
-		nPos++;
+		nPos += nCharSize;
 	}
 	//結果
 	if(nWordLen>0){
@@ -188,7 +188,7 @@ void CLayoutMgr::_DoKutoBurasage(SLayoutWork* pWork) const
 		if( _IsKinsokuPosKuto( GetMaxLineLayout() - pWork->nPosX, nCharKetas ) && IsKinsokuKuto( pWork->cLineStr.At( pWork->nPos ) ) )
 		{
 			pWork->nWordBgn = pWork->nPos;
-			pWork->nWordLen = 1;
+			pWork->nWordLen = CNativeW::GetSizeOfChar( pWork->cLineStr, pWork->nPos );
 			pWork->eKinsokuType = KINSOKU_TYPE_KINSOKU_KUTO;
 		}
 	}
@@ -203,24 +203,17 @@ void CLayoutMgr::_DoGyotoKinsoku(SLayoutWork* pWork, PF_OnLine pfOnLine)
 	 && (pWork->eKinsokuType == KINSOKU_TYPE_NONE) )
 	{
 		// 2007.09.07 kobake   レイアウトとロジックの区別
-		CLayoutInt nCharKetas2 = GetLayoutXOfChar( pWork->cLineStr, pWork->nPos );
-		CLayoutInt nCharKetas3 = GetLayoutXOfChar( pWork->cLineStr, pWork->nPos+1 );
-		bool bLowSurrogate = false;
+		CLogicXInt nCharSize = CNativeW::GetSizeOfChar( pWork->cLineStr, pWork->nPos );
+		CLayoutXInt nCharKetas1 = GetLayoutXOfChar( pWork->cLineStr, pWork->nPos );
+		CLayoutXInt nCharKetas2 = GetLayoutXOfChar( pWork->cLineStr, pWork->nPos + nCharSize );
 
-		if( nCharKetas3 == 0 && pWork->nPos + 2 < pWork->cLineStr.GetLength() )
-		{
-			// サロゲートペア対策(取得した文字幅が0だったら下位側を読み取ったと判断し、次の位置に進ませる)
-			bLowSurrogate = true;
-			nCharKetas3 = GetLayoutXOfChar( pWork->cLineStr, pWork->nPos + 2 );
-		}
-
-		if( _IsKinsokuPosHead( GetMaxLineLayout() - pWork->nPosX, nCharKetas2, nCharKetas3 )
-		 && IsKinsokuHead( pWork->cLineStr.At( pWork->nPos + ( bLowSurrogate ? 2 : 1 ) ) )
+		if( _IsKinsokuPosHead( GetMaxLineLayout() - pWork->nPosX, nCharKetas1, nCharKetas2 )
+		 && IsKinsokuHead( pWork->cLineStr.At( pWork->nPos + nCharSize ) )
 		 && !IsKinsokuHead( pWork->cLineStr.At( pWork->nPos ) )		// 1字前が行頭禁則の対象でないこと
 		 && !IsKinsokuKuto( pWork->cLineStr.At( pWork->nPos ) ) )	// 1字前が句読点ぶら下げの対象でないこと
 		{
 			pWork->nWordBgn = pWork->nPos;
-			pWork->nWordLen = ( bLowSurrogate ? 3 : 2 );
+			pWork->nWordLen = nCharSize + CNativeW::GetSizeOfChar( pWork->cLineStr, pWork->nPos + nCharSize );
 			pWork->eKinsokuType = KINSOKU_TYPE_KINSOKU_HEAD;
 
 			(this->*pfOnLine)(pWork);
@@ -236,13 +229,14 @@ void CLayoutMgr::_DoGyomatsuKinsoku(SLayoutWork* pWork, PF_OnLine pfOnLine)
 	 && ( pWork->nPosX > pWork->nIndent )	//	2004.04.09 pWork->nPosXの解釈変更のため，行頭チェックも変更
 	 && (pWork->eKinsokuType == KINSOKU_TYPE_NONE) )
 	{
-		CLayoutInt nCharKetas2 = GetLayoutXOfChar( pWork->cLineStr, pWork->nPos );
-		CLayoutInt nCharKetas3 = GetLayoutXOfChar( pWork->cLineStr, pWork->nPos+1 );
+		CLogicXInt nCharSize = CNativeW::GetSizeOfChar( pWork->cLineStr, pWork->nPos );
+		CLayoutXInt nCharKetas1 = GetLayoutXOfChar( pWork->cLineStr, pWork->nPos );
+		CLayoutXInt nCharKetas2 = GetLayoutXOfChar( pWork->cLineStr, pWork->nPos + nCharSize );
 
-		if( _IsKinsokuPosTail( GetMaxLineLayout() - pWork->nPosX, nCharKetas2, nCharKetas3 ) && IsKinsokuTail( pWork->cLineStr.At( pWork->nPos ) ) )
+		if( _IsKinsokuPosTail( GetMaxLineLayout() - pWork->nPosX, nCharKetas1, nCharKetas2 ) && IsKinsokuTail( pWork->cLineStr.At( pWork->nPos ) ) )
 		{
 			pWork->nWordBgn = pWork->nPos;
-			pWork->nWordLen = 1;
+			pWork->nWordLen = nCharSize;
 			pWork->eKinsokuType = KINSOKU_TYPE_KINSOKU_TAIL;
 
 			(this->*pfOnLine)(pWork);
@@ -260,7 +254,7 @@ bool CLayoutMgr::_DoTab(SLayoutWork* pWork, PF_OnLine pfOnLine)
 		return true;
 	}
 	pWork->nPosX += nCharKetas;
-	pWork->nPos += CLogicInt(1);
+	pWork->nPos += CNativeW::GetSizeOfChar( pWork->cLineStr, pWork->nPos );
 	return false;
 }
 
@@ -322,9 +316,6 @@ void CLayoutMgr::_MakeOneLine(SLayoutWork* pWork, PF_OnLine pfOnLine)
 			}
 			// 2007.09.07 kobake   ロジック幅とレイアウト幅を区別
 			CLayoutInt nCharKetas = GetLayoutXOfChar( pWork->cLineStr, pWork->nPos );
-//			if( 0 == nCharKetas ){				// 削除 サロゲートペア対策	2008/7/5 Uchi
-//				nCharKetas = CLayoutInt(1);
-//			}
 
 			if( pWork->nPosX + nCharKetas > GetMaxLineLayout() ){
 				if( pWork->eKinsokuType != KINSOKU_TYPE_KINSOKU_KUTO )
@@ -336,7 +327,7 @@ void CLayoutMgr::_MakeOneLine(SLayoutWork* pWork, PF_OnLine pfOnLine)
 					}
 				}
 			}
-			pWork->nPos += 1;
+			pWork->nPos += CNativeW::GetSizeOfChar( pWork->cLineStr, pWork->nPos );
 			pWork->nPosX += nCharKetas;
 		}
 	}
diff --git a/sakura_core/mem/CMemoryIterator.h b/sakura_core/mem/CMemoryIterator.h
index 6f41e873a9..ef985b32b7 100644
--- a/sakura_core/mem/CMemoryIterator.h
+++ b/sakura_core/mem/CMemoryIterator.h
@@ -110,8 +110,6 @@ class CMemoryIterator
 			if( m_nSpacing ){
 				m_nColumn_Delta += CLayoutXInt(CNativeW::GetKetaOfChar(m_pLine, m_nLineLen, m_nIndex) * m_nSpacing);
 			}
-//			if( 0 == m_nColumn_Delta )				// 削除 サロゲートペア対策	2008/7/5 Uchi
-//				m_nColumn_Delta = CLayoutInt(1);
 		}
 	}
 	
diff --git a/sakura_core/mem/CNativeW.h b/sakura_core/mem/CNativeW.h
index e96cb59bf4..a3b2ee3cc5 100644
--- a/sakura_core/mem/CNativeW.h
+++ b/sakura_core/mem/CNativeW.h
@@ -153,19 +153,20 @@ class CNativeW final : public CNative{
 
 public:
 	// -- -- staticインターフェース -- -- //
-	static CLogicInt GetSizeOfChar( const wchar_t* pData, int nDataLen, int nIdx ); //!< 指定した位置の文字がwchar_t何個分かを返す
-	static CHabaXInt GetHabaOfChar( const wchar_t* pData, int nDataLen, int nIdx,
-		bool bEnableExtEol, CCharWidthCache& cache = GetCharWidthCache() );
+	//! 指定した位置の文字がwchar_t何個分かを返す
+	static CLogicInt GetSizeOfChar( const wchar_t* pData, int nDataLen, int nIdx );
+	static CLogicInt GetSizeOfChar( const CStringRef& cStr, int nIdx )
+		{ return GetSizeOfChar( cStr.GetPtr(), cStr.GetLength(), nIdx ); }
 	//! 指定した位置の文字が半角何個分かを返す
 	static CKetaXInt GetKetaOfChar( const wchar_t* pData, int nDataLen, int nIdx,
 		CCharWidthCache& cache = GetCharWidthCache() );
+	static CKetaXInt GetKetaOfChar(const CStringRef& cStr, int nIdx, CCharWidthCache& cache = GetCharWidthCache())
+		{ return GetKetaOfChar(cStr.GetPtr(), cStr.GetLength(), nIdx, cache); }
 	static const wchar_t* GetCharNext( const wchar_t* pData, int nDataLen, const wchar_t* pDataCurrent ); //!< ポインタで示した文字の次にある文字の位置を返します
 	static const wchar_t* GetCharPrev(const wchar_t* pData, size_t nDataLen, const wchar_t* pDataCurrent); //!< ポインタで示した文字の直前にある文字の位置を返します
 
-	static CKetaXInt GetKetaOfChar( const CStringRef& cStr, int nIdx ) //!< 指定した位置の文字が半角何個分かを返す
-	{
-		return GetKetaOfChar(cStr.GetPtr(), cStr.GetLength(), nIdx);
-	}
+	static CHabaXInt GetHabaOfChar( const wchar_t* pData, int nDataLen, int nIdx,
+		bool bEnableExtEol, CCharWidthCache& cache = GetCharWidthCache() );
 	static CLayoutXInt GetColmOfChar( const wchar_t* pData,
 		int nDataLen, int nIdx, bool bEnableExtEol )
 		{ return GetHabaOfChar(pData,nDataLen,nIdx, bEnableExtEol); }
diff --git a/tests/unittests/test-cnative.cpp b/tests/unittests/test-cnative.cpp
index 5982fc2ff5..6a795fd4f2 100644
--- a/tests/unittests/test-cnative.cpp
+++ b/tests/unittests/test-cnative.cpp
@@ -788,12 +788,16 @@ TEST(CNativeW, GetSizeOfChar)
 {
 	// 基本多言語面の文字ならば1を返す。
 	EXPECT_EQ(CNativeW::GetSizeOfChar(L"a", 1, 0), 1);
+	EXPECT_EQ(CNativeW::GetSizeOfChar(CStringRef(L"a", 1), 0), 1);
 	// 範囲外なら0を返す。
 	EXPECT_EQ(CNativeW::GetSizeOfChar(L"", 0, 0), 0);
+	EXPECT_EQ(CNativeW::GetSizeOfChar(CStringRef(L"", 0), 0), 0);
 	// 上位・下位サロゲートの組み合わせであれば2を返す。
 	EXPECT_EQ(CNativeW::GetSizeOfChar(L"\xd83c\xdf38", 2, 0), 2);
+	EXPECT_EQ(CNativeW::GetSizeOfChar(CStringRef(L"\xd83c\xdf38", 2), 0), 2);
 	// 指定位置が下位サロゲートならその他の文字と同様に1を返す。
 	EXPECT_EQ(CNativeW::GetSizeOfChar(L"\xd83c\xdf38", 2, 1), 1);
+	EXPECT_EQ(CNativeW::GetSizeOfChar(CStringRef(L"\xd83c\xdf38", 2), 1), 1);
 }
 
 /*!
@@ -804,12 +808,16 @@ TEST(CNativeW, GetKetaOfChar)
 {
 	// 範囲外なら0を返す。
 	EXPECT_EQ(CNativeW::GetKetaOfChar(L"", 0, 0), 0);
+	EXPECT_EQ(CNativeW::GetKetaOfChar(CStringRef(L"", 0), 0), 0);
 	// 上位サロゲートなら2を返す。
 	EXPECT_EQ(CNativeW::GetKetaOfChar(L"\xd83c\xdf38", 2, 0), 2);
+	EXPECT_EQ(CNativeW::GetKetaOfChar(CStringRef(L"\xd83c\xdf38", 2), 0), 2);
 	// 上位サロゲートに続く下位サロゲートであれば0を返す。
 	EXPECT_EQ(CNativeW::GetKetaOfChar(L"\xd83c\xdf38", 2, 1), 0);
+	EXPECT_EQ(CNativeW::GetKetaOfChar(CStringRef(L"\xd83c\xdf38", 2), 1), 0);
 	// 下位サロゲートだけなら2を返す。
 	EXPECT_EQ(CNativeW::GetKetaOfChar(L"\xdf38", 1, 0), 2);
+	EXPECT_EQ(CNativeW::GetKetaOfChar(CStringRef(L"\xdf38", 1), 0), 2);
 
 	// サクラエディタでは Unicode で表現できない文字コードの破壊を防ぐため、
 	// 不明バイトを下位サロゲートにマップして保持している。
@@ -819,12 +827,17 @@ TEST(CNativeW, GetKetaOfChar)
 	// https://sourceforge.net/p/sakura-editor/patchunicode/57/
 	// http://sakura-editor.sourceforge.net/cgi-bin/cyclamen/cyclamen.cgi?log=unicode&v=833
 	EXPECT_EQ(CNativeW::GetKetaOfChar(L"\xdbff", 1, 0), 2);
-	for (wchar_t ch = 0xdc00; ch <= 0xdcff; ++ch)
+	EXPECT_EQ(CNativeW::GetKetaOfChar(CStringRef(L"\xdbff", 1), 0), 2);
+	for (wchar_t ch = 0xdc00; ch <= 0xdcff; ++ch) {
 		EXPECT_EQ(CNativeW::GetKetaOfChar(&ch, 1, 0), 1);
+		EXPECT_EQ(CNativeW::GetKetaOfChar(CStringRef(&ch, 1), 0), 1);
+	}
 	EXPECT_EQ(CNativeW::GetKetaOfChar(L"\xdd00", 1, 0), 2);
+	EXPECT_EQ(CNativeW::GetKetaOfChar(CStringRef(L"\xdd00", 1), 0), 2);
 
 	// 文字が半角なら1を返す。
 	EXPECT_EQ(CNativeW::GetKetaOfChar(L"a", 1, 0), 1);
+	EXPECT_EQ(CNativeW::GetKetaOfChar(CStringRef(L"a", 1), 0), 1);
 
 	// 文字が全角なら2を返す。
 	class FakeCache : public CCharWidthCache {
@@ -832,6 +845,7 @@ TEST(CNativeW, GetKetaOfChar)
 		bool CalcHankakuByFont(wchar_t c) override { return false; }
 	} cache;
 	EXPECT_EQ(CNativeW::GetKetaOfChar(L"あ", 1, 0, cache), 2);
+	EXPECT_EQ(CNativeW::GetKetaOfChar(CStringRef(L"あ", 1), 0, cache), 2);
 }
 
 /*!